Sunday, June 4, 2017

ISS: Cargo and Crew Transfers Underway

Soyuz MS-03 undocks from the International Space Station. A Progress Supply ship is docked in the background. (Credit: NASA)

On June 2, Soyuz ship MS-03 departed for a return trip to Earth. Rather than the usual three crewmembers, this trip only included two: Oleg Novitskiy (Roscosmos) and Thomas Pesquet (ESA).

Before the departure, a Change of Command ceremony took place.

Peggy Whitson turns over command of the station to Fyodor Yurchikhin. (Credit: NASA TV)

On June 1st, Expedition 51 officially ended when astronaut Peggy Whitson gave command to cosmonaut Fyodor Yurchikhin. With the ceremony completed, the Expedition 52 period did not officially begin until Novitskiy and Pesquet departed for Earth. The two had 196 days in space before leaving on Friday. Crew reinforcements for Expedition 52 will arrive in July.

From L-R: Novistkiy, Whitson, Pesquet. (NASA)

Computer simulation of Soyuz module separations during re-entry process. The crew is located in the center module, which has the heat shield. The service module and crew docking module burn up during re-entry.

Touchdown! Soyuz MS-03 safely lands after firing landing thrusters activate during the final few moments of descent. Landing took place in Kazakhstan.

Meanwhile, there is a resupply mission ending and another one beginning. SpaceX was due to launch a special resupply mission on Friday, but had to postpone for a day because of lightning concerns at the launch site. This mission (CRS-11) would feature the first use of a reusable Dragon cargo ship. Ship number C-106 was last used on mission CRS-4 in September of 2014.

Actual launch of mission CRS-11 took place Saturday June 3. The Falcon 9 rocket took off flawlessly and after ten minutes separated from the Dragon spacecraft, which continued its flight into orbit. The rocket itself however, descended by parachute and engine power to land vertically back at Kennedy on pad LC-13. With a safe landing, the rocket can be refurbished and prepared to be reused on another future flight.

Cygnus resupply spacecraft. (NASA)

While Dragon makes its way to the ISS, another ship is leaving. Early Sunday morning, astronauts Jack Fischer and Peggy Whitson used the station's CanadArm robotic arm to pull the undocked Cygnus spacecraft OA-7 (Named John H. Glenn) from its berth and release it. This move comes a month earlier than scheduled, in an effort to reduce the future workload for the crew. The Cygnus will now move away from the station, and spend a week doing experiments under control from ground flight engineers. The John H. Glenn will deploy several small satellites on Thursday, and after experiments are completed, the craft will de-orbit and burn up over the Pacific Ocean on June 11.